The 84-year-old was targeted during an incident at HMP Bullingdon in Oxfordshire.

A source said that there was a scuffle and the artist and musician was nearby.

"Someone did aim a spit at him, but he was not spat on, and was not physically hurt," the source added.

News of the incident came as it was announced that Harris has applied for permission to appeal against his convictions for a string of indecent assaults.

A spokesman for the Judicial Office confirmed that lawyers had lodged papers at the Court of Appeal this week.

Harris was convicted of 12 indecent assaults on June 30 at Southwark Crown Court - one on an eight-year-old autograph hunter, two on girls in their early teens and a catalogue of abuse of his daughter's friend over 16 years.

The court will now consider whether to grant permission for him to continue with his appeal bid.

Harris, a family favourite for decades, was finally unmasked as a predator who was fixated with under-age girls during his trial, with jurors told how his 16-year campaign of sex abuse against his daughter's friend ''haunted'' her and made her abandon her dreams as he continued to be adored by millions of fans worldwide.

His fall from grace was underlined as he was stripped of a Bafta fellowship and accolades in his native Australia were removed, and he faces losing his prestigious CBE.

The performer's multi-million pound fortune is also at risk from potential compensation claims.

Harris was jailed for five years and nine months for the sex abuse, meaning that he is due to serve just under three years for the crimes, which spanned between 1968 and 1986.

Earlier this week the Attorney General's Office confirmed that the sentence would not be referred to the Court of Appeal for being unduly lenient.

Attorney General Jeremy Wright decided not to take action despite his office receiving 150 complaints about the leniency of Harris's sentence, of which he will serve half, although it only takes one complaint to trigger the review process.